In my system, for my kind of music, I prefer to reduce the entire distortion spectra by 40% (even and odd), instead of having a DAC with mostly odd-harmonics distortion.

Odd-harmonic distortion sounds screechy and not musical at all, it has no pitch relationship to the instrument's natural timbre, therefore sounds dissonant.
IMO 3rd and 5th harmonic distortion sounds like an underbiased solid state amplifier.

Even-harmonic distortion is similar to the musical instruments natural timbre, therefore it sounds musical (consonant), it is mostly ignored by the human auditory system (AFAIK up to 3 % ).
I hope this helps

Well, I guess the question comes down to which configuration is most important for percieved reproduction quality...

I am not an expert but as you indicate I've read that the logic for parallel dacs is the they will average linearity errors but on the other hand is that not what a balancen configuration will do as well?

Besides linerity errors I can see a balance configuration being able to supress noice induced in powersupplies and cables.

I was looking for real-world experiance as I understand there is no real scientific explanation why paralell dacs sound better.

I can't quite see how parallelling DACs could do more than
reduce errors due to individual variations between the DACs.
Howver, perhaps we'd better clear up what we mean with
parallelling DACs, so we avoid confusing each other. I have
taken the term to mean that two DACs are fed identical data
and the outputs are summed/averaged, but perhaps that is
not what others mean? Similarly, balanced DACs would in
my understanding be two DACs where one is fed the
complement of the data to the other one, so we get a
balanced signal between the two DAC outputs.